JPH04523B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to an optical stylus device.

Measurement of distance (length, position) is fundamental in measuring the shape, movement, deformation, etc. of objects. The present invention relates to an optical stylus device used for measuring such distances.

Conventional technology There are various distance detection methods used to measure the shape, motion, deformation, etc. of objects, from those using mechanical stylus to those using various physical phenomena such as light, sound waves, electricity, and magnetism. measurement methods have been devised and used. An optical stylus device is used as a non-contact distance sensor to replace the mechanical stylus method from the viewpoint of measuring objects that are deformed or moving objects, and improving measurement speed. has been done.

FIG. 2 shows this conventional optical stylus device. Radial position detection sensors 1 ₁ , 1 ₂ , 1 ₃ , 1 ₄ are on the observation plane P
An imaging lens 2 and a cylindrical mirror 3 are arranged along the projection direction of the light beam B from the center of the observation plane P. The light beam B projected onto an arbitrary gauge point T on the object to be measured 4 is reflected from the gauge point T,
It is further reflected toward the imaging lens 2 by the cylindrical mirror 3,
An image is formed on the observation plane P as a circle with radius r. The distance from the observation plane P to the reference point T on the object to be measured is a direct function of the radius r (see FIG. 3).

Problems to be Solved by the Invention This conventional optical stylus device is effective in detecting distances in the Z-axis direction, but distances in axial directions other than the Z-axis cannot be detected unless the orientation of the optical stylus device itself is changed. I can't. When an object to be measured has a deep hole or recess with a relatively small diameter, conventional optical stylus devices cannot measure the depth and radial size of the hole or recess. It was not possible to measure it.

Problems to be Solved by the Invention An object of the present invention is to provide an optical stylus device that can perform three-dimensional distance measurement in multiple axes.

Means and Effects for Solving the Problems The optical stylus device of the present invention optically performs three-dimensional distance measurement in multiple axes, including a radial position detection sensor, an imaging lens, and a cylindrical or conical reflecting mirror. and a multi-axis direction projection means arranged along the optical axis of the imaging lens in the projection direction of the light beam, and each of the multi-axis direction projection means has its center portion aligned with the optical axis, and the multi-axis direction projection means The central part is a semi-transparent mirror, arranged in the cross direction and mutually.
It consists of at least one elongated reflector, the other part of which is a perfect reflector.

The light beam from the light source is projected through the imaging lens onto the intersecting part (semi-transparent mirror part) of the reflector, where it is projected in the optical axis direction (Z-axis) and in the direction that intersects the optical axis direction and intersects each other (X-axis). splits the light beam into two (axis, Y axis). The light beams in each direction are projected onto the object to be measured, and the reflected light from the projection points in the X-axis and Y-axis directions is reflected from the perfect reflection mirror part of the reflector to a cylindrical mirror or a conical mirror, and the light beams in the Z-axis The reflected light from the projection point in the direction enters the cylindrical mirror or conical mirror from between the overlapping of the two mutually intersecting reflectors, and is directed from this cylindrical mirror or conical mirror again to the imaging lens. The light is reflected by the image pickup lens and projected toward the radial position detection sensor to form an image. The distance in each direction is detected from the radius of this imaging position.

Embodiment An embodiment of the present invention is shown in FIG. _{Radial position detection sensor 1 _ _ _ _} It is located in Along the projection direction of the light beam, there is an imaging lens 2, a cylindrical surface or a conical surface reflecting mirror 3, and a first and second lens whose center part is a semi-transparent mirror and the other parts are total reflection mirrors as beam projection means in three axial directions. Two reflectors are used, and these reflectors are arranged with their center portions aligned with the optical axis and intersecting the optical axis as well as intersecting each other. If they intersect at right angles, it is possible to project onto the three axes of the X, Y, and Z axes, but they may also intersect at angles other than right angles. To make the amount of light beams in three directions the same, for example, the transmittance of the first reflector should be set to 70% and the transmittance of the second reflector should be set to 50%, taking into account loss due to reflection. Bye.

In operation, position sensing in multiple axes is
This is done separately in the Y and Z axis directions. The light beam B projected along the optical axis is converged by the imaging lens 2, travels straight through the reflector 3, and 70% of its light intensity passes through the center of the first reflector ₅₁ , while the remaining
30% points in the radial direction of the concave surface towards the X-axis direction
Projected to T _x . 50% of the transmitted light beam is transmitted at the center of the second reflector ₅₂ , and the remaining 50% is transmitted at the radial point of the concave surface in the Y-axis direction.
Projected to T _y . The light beam transmitted through the first and second reflectors travels straight along the optical axis, that is, the Z axis, and is projected to a point T _z at the bottom of the concave surface. these points
The reflected beams from T _X and T _Y are reflected from the fully reflective mirror portions of the first and second reflectors toward the mirror surface within the reflector 3. Further, the reflected beam from T _Z passes between the first and second reflectors and enters the reflecting mirror 3. The reflected beam from the mirror surface of the reflector 3 passes through the imaging lens 2 and forms an image on the observation surface, and the sensor 1
The distance from the radius of the imaging position to the points T _x , T _y , and T _z on each axis is determined.

Although a cylindrical mirror is used in this embodiment, a conical mirror may also be used. When a conical mirror is arranged to widen from the imaging lens toward the object to be measured, the relationship between the image position detection radius and the distance is expressed by a curve that extends above the curve approximately along the curve in Figure 3. When a conical mirror is arranged to taper toward the object to be measured, the relationship between the image position detection radius and the distance is represented by a curve that extends below the curve approximately along the curve in FIG.

This example uses two reflectors to measure along three axes: X, Y, and Z. However, 1
If two reflectors are used and placed at an angle along the optical axis, the reflected beam will extend toward the optical axis, and the reflected beam of T _X or T _Y will be used together with the straight beam from T _Z. Then, the slope of the concave surface can be measured. Also, by increasing the number of reflectors, 4
Axis and 5-axis measurements are also possible.

Effects of the Invention According to the present invention, it is possible to three-dimensionally measure a concave surface or hole of an object to be measured in a multiaxial direction.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the invention. FIG. 2 is a schematic diagram of a conventional optical stylus device. FIG. 3 is a graph showing the relationship between the position in the optical axis direction and the imaging position detection radius of a conventional optical stylus device. In the figure: 1 _x , 1 _-x ; 1 _y , 1 _-y ; 1 _z , 1 _-z ...Radial position detection sensor, 2...Imaging lens, 3...
...Cylindrical mirror, 4...Object to be measured, ₅₁ , ₅₂ ...First and second reflectors.

Claims (1)

[Claims] 1. A radial position detection sensor, an imaging lens, a cylindrical surface or a conical surface reflector, and a multi-axial projection means are arranged along the optical axis of the imaging lens in the projection direction of the light beam, and the multi-axial projection means is arranged along the optical axis of the imaging lens. are arranged with their respective central portions aligned with the optical axis, in a direction crossing the optical axis, and intersecting each other, with the central portion being a semi-transparent mirror and the other portions being fully reflective mirrors. An optical stylus device characterized by two elongated reflectors.